1. Field of the Invention
The present invention relates to a cooking apparatus which uses microwaves and, more particularly, to a cooking apparatus having improved uniform heating performance.
2. Description of the Conventional Art
Generally, a cooking apparatus utilizing microwaves which are irradiated to a non-conducting substance such as foods (hereinafter, referred to as “contents” or a “cooking object”) thereby cooking an inside of the contents evenly in a short time due to the molecular vibrations in the contents (or the cooking object).
The cooking apparatus which uses microwaves includes a microwave oven (MWO) which cooks the contents in the cooking chamber with microwaves, an over the range (OTR), arranged at an upper side of the cooking apparatus, and having a hood function which exhausts smoke and smell (or odor), an electric oven having a heater and a cooking function which uses microwaves.
The conventional cooking apparatus using microwaves, however, has a disadvantage in that the cooking object received in the cooking chamber is heated unevenly (or unequally), as the microwaves are radiated unevenly into the cooking chamber. That is, the microwave field is formed unevenly in the cooking chamber due to the general cooking apparatus being organized (or arranged) such that the microwaves are radiated from a deflected place in the cooking chamber.
More recently, a stirrer stirring the microwaves or an antenna radiating the microwaves are rotatably installed to be rotated at a part (or location) where the microwaves are radiated, to overcome the aforementioned disadvantage. However, the improvement of uniform heating performance, i.e., using stirrers and antennas has been limited.
Further, the conventional cooking apparatus which uses microwaves has a disadvantage in that there is a limit in which microwaves can be optimized in accordance with the load of the cooking object or the cooking mode, as the microwave is steadily radiated in the cooking chamber. That is, the performance of the conventional cooking apparatus is developed as focusing (or directed to) a middle point satisfying both of the light load and heavy load of the contents to be cooked (or cooking objects). Therefore, the microwave field has to be readjusted, even if there is a small change in the size and shape of the cooking chamber, and it becomes impossible to realize the optimization and maximization of the cooking performance even according to load and cooking mode of the contents.